[ltt-dev] [UST PATCH] Code base to fix the print errors in UST (v4)

Mathieu Desnoyers compudj at krystal.dyndns.org
Thu Mar 3 10:48:54 EST 2011


* Yannick Brosseau (yannick.brosseau at gmail.com) wrote:
> From: David Goulet <david.goulet at polymtl.ca>
> 
> Update:
> v2: Use commit_seq instead of commit_count to fix a consumerd segfault when accessing
> commit_count, since it is not mapped.
> v3: Remove commented out code
> v4: Remove unused variable

merged, thanks!

Mathieu

> 
> Signed-off-by: Yannick Brosseau <yannick.brosseau at gmail.com>
> Signed-off-by: David Goulet <david.goulet at polymtl.ca>
> ---
>  include/ust/ustconsumer.h       |    4 ++
>  libust/buffers.c                |   82 ---------------------------------------
>  libustconsumer/libustconsumer.c |    4 ++
>  libustconsumer/lowlevel.c       |   72 +++++++++++++++++++++++++++++++---
>  4 files changed, 74 insertions(+), 88 deletions(-)
> 
> diff --git a/include/ust/ustconsumer.h b/include/ust/ustconsumer.h
> index e07b75e..f99f8f1 100644
> --- a/include/ust/ustconsumer.h
> +++ b/include/ust/ustconsumer.h
> @@ -57,6 +57,10 @@ struct buffer_info {
>  	int n_subbufs;
>  	/* size of each subbuffer */
>  	int subbuf_size;
> +	/* subbuf size count order */
> +	int subbuf_size_order;
> +	/* alloc size of all subbuf */
> +	int alloc_size;
>  
>  	/* the buffer information struct */
>  	void *bufstruct_mem;
> diff --git a/libust/buffers.c b/libust/buffers.c
> index 4011b64..732e03d 100644
> --- a/libust/buffers.c
> +++ b/libust/buffers.c
> @@ -254,12 +254,8 @@ unmap_buf:
>  	return -1;
>  }
>  
> -static void ltt_relay_print_buffer_errors(struct ust_channel *chan, int cpu);
> -
>  static void close_buf(struct ust_buffer *buf)
>  {
> -	struct ust_channel *chan = buf->chan;
> -	int cpu = buf->cpu;
>  	int result;
>  
>  	result = shmdt(buf->buf_data);
> @@ -267,8 +263,6 @@ static void close_buf(struct ust_buffer *buf)
>  		PERROR("shmdt");
>  	}
>  
> -	free(buf->commit_count);
> -
>  	result = close(buf->data_ready_fd_read);
>  	if (result < 0) {
>  		PERROR("close");
> @@ -278,9 +272,6 @@ static void close_buf(struct ust_buffer *buf)
>  	if (result < 0 && errno != EBADF) {
>  		PERROR("close");
>  	}
> -
> -	/* FIXME: This spews out errors, are they real?:
> -	 * ltt_relay_print_buffer_errors(chan, cpu); */
>  }
>  
>  
> @@ -517,78 +508,6 @@ int ust_buffers_put_subbuf(struct ust_buffer *buf, unsigned long uconsumed_old)
>  	return 0;
>  }
>  
> -static void ltt_relay_print_subbuffer_errors(
> -		struct ust_channel *channel,
> -		long cons_off, int cpu)
> -{
> -	struct ust_buffer *ltt_buf = channel->buf[cpu];
> -	long cons_idx, commit_count, commit_count_sb, write_offset;
> -
> -	cons_idx = SUBBUF_INDEX(cons_off, channel);
> -	commit_count = uatomic_read(&ltt_buf->commit_count[cons_idx].cc);
> -	commit_count_sb = uatomic_read(&ltt_buf->commit_count[cons_idx].cc_sb);
> -
> -	/*
> -	 * No need to order commit_count and write_offset reads because we
> -	 * execute after trace is stopped when there are no readers left.
> -	 */
> -	write_offset = uatomic_read(&ltt_buf->offset);
> -	WARN( "LTT : unread channel %s offset is %ld "
> -		"and cons_off : %ld (cpu %d)\n",
> -		channel->channel_name, write_offset, cons_off, cpu);
> -	/* Check each sub-buffer for non filled commit count */
> -	if (((commit_count - channel->subbuf_size) & channel->commit_count_mask)
> -	    - (BUFFER_TRUNC(cons_off, channel) >> channel->n_subbufs_order) != 0) {
> -		ERR("LTT : %s : subbuffer %lu has non filled "
> -			"commit count [cc, cc_sb] [%lu,%lu].\n",
> -			channel->channel_name, cons_idx, commit_count, commit_count_sb);
> -	}
> -	ERR("LTT : %s : commit count : %lu, subbuf size %zd\n",
> -			channel->channel_name, commit_count,
> -			channel->subbuf_size);
> -}
> -
> -static void ltt_relay_print_errors(struct ust_trace *trace,
> -		struct ust_channel *channel, int cpu)
> -{
> -	struct ust_buffer *ltt_buf = channel->buf[cpu];
> -	long cons_off;
> -
> -	/*
> -	 * Can be called in the error path of allocation when
> -	 * trans_channel_data is not yet set.
> -	 */
> -	if (!channel)
> -	        return;
> -
> -//ust//	for (cons_off = 0; cons_off < rchan->alloc_size;
> -//ust//	     cons_off = SUBBUF_ALIGN(cons_off, rchan))
> -//ust//		ust_buffers_print_written(ltt_chan, cons_off, cpu);
> -	for (cons_off = uatomic_read(&ltt_buf->consumed);
> -			(SUBBUF_TRUNC(uatomic_read(&ltt_buf->offset),
> -				      channel)
> -			 - cons_off) > 0;
> -			cons_off = SUBBUF_ALIGN(cons_off, channel))
> -		ltt_relay_print_subbuffer_errors(channel, cons_off, cpu);
> -}
> -
> -static void ltt_relay_print_buffer_errors(struct ust_channel *channel, int cpu)
> -{
> -	struct ust_trace *trace = channel->trace;
> -	struct ust_buffer *ltt_buf = channel->buf[cpu];
> -
> -	if (uatomic_read(&ltt_buf->events_lost))
> -		ERR("channel %s: %ld events lost (cpu %d)",
> -			channel->channel_name,
> -			uatomic_read(&ltt_buf->events_lost), cpu);
> -	if (uatomic_read(&ltt_buf->corrupted_subbuffers))
> -		ERR("channel %s : %ld corrupted subbuffers (cpu %d)",
> -			channel->channel_name,
> -			uatomic_read(&ltt_buf->corrupted_subbuffers), cpu);
> -
> -	ltt_relay_print_errors(trace, channel, cpu);
> -}
> -
>  static int map_buf_structs(struct ust_channel *chan)
>  {
>  	void *ptr;
> @@ -721,7 +640,6 @@ static void remove_channel(struct ust_channel *chan)
>  	free(chan->buf_struct_shmids);
>  
>  	free(chan->buf);
> -
>  }
>  
>  static void ltt_relay_async_wakeup_chan(struct ust_channel *ltt_channel)
> diff --git a/libustconsumer/libustconsumer.c b/libustconsumer/libustconsumer.c
> index c51b106..ef54fe8 100644
> --- a/libustconsumer/libustconsumer.c
> +++ b/libustconsumer/libustconsumer.c
> @@ -353,6 +353,10 @@ struct buffer_info *connect_buffer(struct ustconsumer_instance *instance, pid_t
>  		goto close_fifo;
>  	}
>  
> +	/* Set subbuffer's information */
> +	buf->subbuf_size_order = get_count_order(buf->subbuf_size);
> +	buf->alloc_size = buf->subbuf_size * buf->n_subbufs;
> +
>  	/* attach memory */
>  	buf->mem = shmat(buf->shmid, NULL, 0);
>  	if(buf->mem == (void *) 0) {
> diff --git a/libustconsumer/lowlevel.c b/libustconsumer/lowlevel.c
> index 730dd11..fdc4e24 100644
> --- a/libustconsumer/lowlevel.c
> +++ b/libustconsumer/lowlevel.c
> @@ -31,6 +31,66 @@
>  #define LTT_MAGIC_NUMBER 0x00D6B7ED
>  #define LTT_REV_MAGIC_NUMBER 0xEDB7D600
>  
> +
> +static void ltt_relay_print_subbuffer_errors(
> +		struct buffer_info *buf,
> +		long cons_off, int cpu)
> +{
> +	struct ust_buffer *ust_buf = buf->bufstruct_mem;
> +	long cons_idx, commit_count, commit_count_mask, write_offset;
> +
> +	cons_idx = SUBBUF_INDEX(cons_off, buf);
> +	commit_count = uatomic_read(&ust_buf->commit_seq[cons_idx]);
> +	commit_count_mask = (~0UL >> get_count_order(buf->n_subbufs));
> +
> +	/*
> +	 * No need to order commit_count and write_offset reads because we
> +	 * execute after trace is stopped when there are no readers left.
> +	 */
> +	write_offset = uatomic_read(&ust_buf->offset);
> +	WARN( "LTT : unread channel %s offset is %ld "
> +			"and cons_off : %ld (cpu %d)\n",
> +			buf->channel, write_offset, cons_off, cpu);
> +	/* Check each sub-buffer for non filled commit count */
> +	if (((commit_count - buf->subbuf_size) & commit_count_mask)
> +			- (BUFFER_TRUNC(cons_off, buf) >> get_count_order(buf->n_subbufs)) != 0) {
> +		ERR("LTT : %s : subbuffer %lu has non filled "
> +				"commit count [seq] [%lu].\n",
> +				buf->channel, cons_idx, commit_count);
> +	}
> +	ERR("LTT : %s : commit count : %lu, subbuf size %d\n",
> +			buf->channel, commit_count,
> +			buf->subbuf_size);
> +}
> +
> +static void ltt_relay_print_errors(struct buffer_info *buf, int cpu)
> +{
> +	struct ust_buffer *ust_buf = buf->bufstruct_mem;
> +	long cons_off;
> +
> +	for (cons_off = uatomic_read(&ust_buf->consumed);
> +			(SUBBUF_TRUNC(uatomic_read(&ust_buf->offset), buf)
> +				- cons_off) > 0;
> +			cons_off = SUBBUF_ALIGN(cons_off, buf))
> +		ltt_relay_print_subbuffer_errors(buf, cons_off, cpu);
> +}
> +
> +static void ltt_relay_print_buffer_errors(struct buffer_info *buf, int cpu)
> +{
> +	struct ust_buffer *ust_buf = buf->bufstruct_mem;
> +
> +	if (uatomic_read(&ust_buf->events_lost))
> +		ERR("channel %s: %ld events lost (cpu %d)",
> +				buf->channel,
> +				uatomic_read(&ust_buf->events_lost), cpu);
> +	if (uatomic_read(&ust_buf->corrupted_subbuffers))
> +		ERR("channel %s : %ld corrupted subbuffers (cpu %d)",
> +				buf->channel,
> +				uatomic_read(&ust_buf->corrupted_subbuffers), cpu);
> +
> +	ltt_relay_print_errors(buf, cpu);
> +}
> +
>  /* Returns the size of a subbuffer size. This is the size that
>   * will need to be written to disk.
>   *
> @@ -103,12 +163,6 @@ void finish_consuming_dead_subbuffer(struct ustconsumer_callbacks *callbacks, st
>  
>  		struct ltt_subbuffer_header *header = (struct ltt_subbuffer_header *)((char *)buf->mem+i_subbuf*buf->subbuf_size);
>  
> -		if((commit_seq & commit_seq_mask) == 0) {
> -			/* There is nothing to do. */
> -			/* FIXME: is this needed? */
> -			break;
> -		}
> -
>  		/* Check if subbuf was fully written. This is from Mathieu's algorithm/paper. */
>  		/* FIXME: not sure data_size = 0xffffffff when the buffer is not full. It might
>  		 * take the value of the header size initially */
> @@ -137,8 +191,14 @@ void finish_consuming_dead_subbuffer(struct ustconsumer_callbacks *callbacks, st
>  		if(callbacks->on_read_partial_subbuffer)
>  			callbacks->on_read_partial_subbuffer(callbacks, buf, i_subbuf, valid_length);
>  
> +		/* Manually increment the consumed offset */
> +		/* TODO ybrosseau 2011-03-02: Should only be done if the previous read was successful */
> +		uatomic_add(&ustbuf->consumed, buf->subbuf_size);
> +
>  		if(i_subbuf == last_subbuf % buf->n_subbufs)
>  			break;
>  	}
> +
> +	ltt_relay_print_buffer_errors(buf, buf->channel_cpu);
>  }
>  
> -- 
> 1.7.2.3
> 
> 
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> ltt-dev at lists.casi.polymtl.ca
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> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com




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